In terms of running motor when on water - I dont always have the motor
right down, even trimmed up a bit it usually has enough torque to get
out of hole. I believe the 60 Bigfoot has the larger 115hp bottom end?
Trim:
Trim is what you use far more often than the throttle.
At still, the trim is right down, if it is not the boat struggles to get over the bow wave.. basically crap hole shot if up, even a little up.
Also it trim is up and moving off the plane down thru boats or a creek, your steering is crap
The boat goes over the bow wave and onto the plane, now you bring the trim up to just before ventation.. should be able to hear it, and/ or porpoising (bow bouncing excessively)
If this is not the cruise speed you want then increase rpms to just below for that cruise speed.. then trim up. the rpms and speed increase due to more push and less drag.
Well trimmed saves a huge amount of fuel.
If slow a little by throttle, drop the trim accordingly.
You are at a cruise speed, a wave comes up you have to cross.. line up and just before, drop the trim. Bow drops, speed drops and you go over smooth.. All with trim button... withing commonsense reason of course.
Get into chop, may have to drop throttle a little, if small chop simply dropping trim slightly keeps a reasonable comfortable ride at good planing speed and economy without falling off the plane.
Faster you go, the more you can trim for that faster speed
Manufactures design their trims, engine size to be fitted so
hulls are well powered.. by weight.
Displacement hulls are a totally different kettle of fish.
Yeah looks like total gross weight, by estimate ,and by an estimated calc of WoT due to possible not trimmed was well as should and revised hull constant would come in at about 950kg.
60hp 2S will give a WoT around 32 mph 4S 34 mph
75 2S about 36 mph 4S 38 mph
90 2S about 40 mph 90 4S 42 mph
A nicely powered you would have a WoT around 38mph
Well powered 42 mph
To get the best out of your hull on that boat with that loading a min 90 2S or 4S
This is all based on performance economy, weight etc
Not manufactures construction specs which I do not know.
The difference even between a manufactures mid of the hp range (usually min powered by weight) and their max hp rating in hull performance is HUGE in most cases. Thu some manufactures have trouble meeting Safety specs and even their max powered rating is still mediocre
I hope this info gives you the information as to fix trim or repower, and if re power what to repower to.
I strongly advise, even if bit over budget, and intend to keep the boat for a long time... repower well.
If re power low, and going to sell.. do what some (far too many) sale yards do.. strip as much weight out, use a light weight sales rep to demo/ sea trial and dump a prop on next pitch up.
One of my most disheartening things are ppl who contact me..And this includes experienced guys surprisingly too often
" my new boat doesnt go as well as when we trialed or in reveiws... Can we change props to make it do so"
They are on budget, gone for as much boat and compromised on power in the total price...
This is their pride joy.. gone for broke..
And I have to explain something they just dont wish to acknowledge or have issues excepting...
Im not a diplomatic person, and it hurts my heart when I do so.
As to building my data base..
alloy boats from the 90s period in particular when manufactures went from thin light panels to thicker welded panels, more weight, and hulls dont get 1000s of pin holes, is a bit confusing due to significant changes in weights.
These days alloy and glass hulls are very similar in weight, differences are in things like cabin or not in both cases.